Li-Decorated Fullerenes: A DFT Study

Abstract

Density functional calculations have been applied to study the structure, stability and aromaticity of Li-decorated non-IPR fullerene cages, Cn with n = 44, 46, 48, and 50, and IPR fullerene cages, Cn with n = 60, 70, 76, and 84. Based on our results, the binding energies per Li atom for Li12Cn clusters depend on the type and size of the cages. As of Li-decorated IPR fullerenes, where pentagons are isolated, there is virtually no interaction between the Li atoms, so that the binding energies for the Li-decorated IPR Cn fullerenes are obtained to be larger than those for the Li-decorated non-IPR ones. The C–C bond lengths in the pentagons of Li12Cn clusters are enlarged relative to those of pristine Cn clusters. Based on NBO analysis, charge transfer (~ 0.5e) from Li to the fullerene cage makes the Li atoms positively charged. NICS data suggest that the degree of aromaticity in C60, C76, and C84 cages increases upon formation of the Li-decorated Cn clusters while more positive NICS values are obtained for C70 and the smaller fullerenes with Li decoration of the cages.